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Asteroid 2004 BL86 made a relatively close pass yesterday. The asteroid passed about 3.1 lunar distances from Earth or 1.2 million km / 745,000 miles. In cosmic scales that is indeed close. The asteroid is 325 meters / 1,100 feet in diameter, not something we would want to hit us!

Scientists used the Deep Space Network antenna at Goldstone California took took radar images of the asteroid and assembled 20 of them into this video and look at what they found – the asteroid has a moon! Actually about 16 percent of the near-Earth population of asteroids of 200 meters in diameter (655 feet) have moons and a few have two. This particular moon is 70 meters (230 feet) across.

The observations of the asteroid enabled scientists to get data on the orbit to predict future close passes and this asteroid will not make another pass this close for 200 years. We do have others though, the next known asteroid to make a close pass is called 1999 AN10 in 2027.

The asteroid was found on Jan. 30, 2004, by the Lincoln Near-Earth Asteroid Research (LINEAR) survey in White Sands, New Mexico, one of a handful of observing groups around the world looking for these very difficult to find objects.

Vesta and Ceres are two of the larger bodies in the asteroid belt that lies between Mars and Jupiter and Ceres is the larger of the two. There are thousands of asteroids in the belt, however when we see the asteroid belt in the movies we always see the spaceships having to weave their way through a maze of rocks. It isn’t even close to being accurate the distribution is such that on average the distance between asteroids is about twice the Earth to Moon distance.

There was speculation the asteroid belt was created by pieces of planet that either never formed or broke apart. We know this isn’t the case, more than likely the belt is “left-over” bits. It is estimated that if all the asteroids were put together to make one body, that body would only be around 1500 km in diameter.

There is much knowledge to be gained by the Ceres visit. Dawn will be making the approach phase to Ceres on 26 December when the speed and trajectory will be tweaked so the spacecraft will be captured by Ceres’ gravitational field in March 2015.

What are the largest asteroids? Here are the top 11. Yes I made a top 11 so I could include 3 Juno.

The number before the name is the discovery sequence and has nothing to do with size. You can get the particulars at our Asteroids page.

Here’s a great map especially if you like fireballs as much as I do. As you will read below it is a map of small asteroid strikes. I find the distribution of daytime/nighttime remarkable. Sure it’s about 50/50 as you would expect but I’d think the daytime ones would be more difficult to detect – apparently not.

Check out the links at the end of the article.

From NASA’s Near Earth Object (NEO) Program:

A map released today by NASA’s Near Earth Object (NEO) Program reveals that small asteroids frequently enter and disintegrate in the Earth’s atmosphere with random distribution around the globe. Released to the scientific community, the map visualizes data gathered by U.S. government sensors from 1994 to 2013. The data indicate that Earth’s atmosphere was impacted by small asteroids, resulting in a bolide (or fireball), on 556 separate occasions in a 20-year period. Almost all asteroids of this size disintegrate in the atmosphere and are usually harmless. The notable exception was the Chelyabinsk event which was the largest asteroid to hit Earth in this period. The new data could help scientists better refine estimates of the distribution of the sizes of NEOs including larger ones that could pose a danger to Earth.

Finding and characterizing hazardous asteroids to protect our home planet is a high priority for NASA. It is one of the reasons NASA has increased by a factor of 10 investments in asteroid detection, characterization and mitigation activities over the last five years. In addition, NASA has aggressively developed strategies and plans with its partners in the U.S. and abroad to detect, track and characterize NEOs. These activities also will help identify NEOs that might pose a risk of Earth impact, and further help inform developing options for planetary defense.

The public can help participate in the hunt for potentially hazardous Near Earth Objects through the Asteroid Grand Challenge, which aims to create a plan to find all asteroid threats to human populations and know what to do about them. NASA is also pursuing an Asteroid Redirect Mission (ARM) which will identify, redirect and send astronauts to explore an asteroid. Among its many exploration goals, the mission could demonstrate basic planetary defense techniques for asteroid deflection.

On 07 September 2014, asteroid 2014 RC will flyby by the Earth. It will be a very close flyby too, only 40,000 km / 25,000 miles from Earth. The orbit will pose no danger to us. Even so according to NASA (see below), 2014 RC could even be visible as it will be around a magnitude 11 making it visible in small telescopes provided you have dark skies when it passes by at 18:18 UT when it will be over New Zealand when it makes this close approach.

In case you are in a place you might be able to see the fly-by, you can get the ephemeris here from the IAU Minor Planet Center.

A small asteroid, designated 2014 RC, will safely pass very close to Earth on Sunday, Sept. 7, 2014. At the time of closest approach, based on current calculations to be about 2:18 p.m. EDT (11:18 a.m. PDT / 18:18 UTC), the asteroid will be roughly over New Zealand. From its reflected brightness, astronomers estimate that the asteroid is about 60 feet (20 meters) in size.

A few days ago you may recall there was an asteroid that passed by Earth. The asteroid passed about three times further from us than our moon. Yes that is quite a ways out, but compared to cosmic distances, pretty close.

NASA was able to get some great images of the more than 366 meter (1200 ft) long oblong shaped rock once it had passed. The video above was pieced together from images taken at a range of 1.25 and 1.39 million km (774,000 to 864,000 miles).

The images were captured by the 70-meter Goldstone antenna working with the Arecibo Observatory in Puerto Rico.

As an aside: Arecibo is located in a seismically active area being not far from the Caribbean plate boundary. Generally the quakes are fairly small, for example yesterday 14 June there was a magnitude 2.7 quake at a depth of 26 km (22.4 miles) occurred 75 km (47 miles) out in the ocean and that was among eight occurring in the previous 24 hours having magnitudes of 2.7 to 3.2. Sure those are pretty small but I wonder if they are noticed by the observatory especially during an observing run.

The same could be asked of the ESO and Keck now that I think of it, it’s just that Arecibo is so huge.

The Mars rover, Curiosity takes the first image of an asteroid from Mars. Credit: NASA/JPL-Caltech/MSSS/Texas A&M

The Curiosity has taken the first image of an asteroid taken from the surface of the Red Planet.

You will notice the asteroids and stars are streaks thanks to the 12 second exposure and the planetary rotation. The Martian rotates about its axis in 24.6 hours, only slightly longer than it does here on Earth.

The other object is the little moon Deimos. The image was taken on Sol 606 or 20 April 2014 (PDT).

The Mast Camera (Mastcam) on NASA’s Curiosity Mars rover has captured the first image of an asteroid taken from the surface of Mars. The night-sky image actually includes two asteroids: Ceres and Vesta, plus one of Mars’ two moons, Deimos, which may have been an asteroid before being captured into orbit around Mars. The image was taken after nightfall on the 606th Martian day, or sol, of Curiosity’s work on Mars (April 20, 2014, PDT). In other camera pointings the same night, the Mastcam also imaged Mars’ larger moon, Phobos, plus the planets Jupiter and Saturn.

I first saw this and thought Hubble caught a comet breaking up, turns out it isn’t it’s an asteroid! Not to mention another Hubble first. The four largest fragments are as much as 200 meters in diameter.

“This is a rock. Seeing it fall apart before our eyes is pretty amazing,” said David Jewitt of UCLA, USA, who led the astronomical forensics investigation.

I must confess I’ve never really considered this before and the way the press release is worded leaves me with the question: are these “contact binaries” actually two separate asteroids or are they just sort of stuck together by whatever (like gravitationally bound, impact fused etc)?

The NASA press release:

A collage of radar images of near-Earth asteroid 2006 DP14 was generated by NASA scientists using the 230-foot (70-meter) Deep Space Network antenna at Goldstone, Calif., on the night of Feb. 11, 2014.

Delay-Doppler radar imaging revealed that the asteroid is about 1,300 feet (400 meters) long, 660 feet (200 meters) wide, and shaped somewhat like a big peanut. The asteroid’s period of rotation is about six hours. The asteroid is of a type known as a “contact binary” because it has two large lobes on either end that appear to be in contact. Previous radar data from Goldstone and the Arecibo Observatory in Puerto Rico has shown that at least 10 percent of near-Earth asteroids larger than about 650 feet (200 meters) have contact binary shapes like that of 2006 DP14. The data were obtained over an interval of 2.5 hours as the asteroid completed about half a revolution. The resolution is about 60 feet (19 meters) per pixel.

The data were obtained on Feb. 11 between 9:03 a.m. and 11:27 p.m. PST (12:03 a.m. to 2:27 a.m. EST on Feb. 12). At the time of the observations, the asteroid’s distance was about 2.6 million miles (4.2 million kilometers) from Earth. That is about 11 times the average distance between Earth and its moon. The asteroid’s closest approach to Earth occurred on Feb. 10, at a distance of about 1.5 million miles (2.4 million kilometers).Continue reading →